A coating film transfer tool is used for transferring a correction film for correction, an adhesive, a decorative coating film, or the like onto a receiving surface. The transfer tool usually employs a coating film tape comprising a layer of coating film layer on a base material.
In order to notify the user when the tape supply in the transfer tool is nearly exhausted, a contrasting length of tape, referred to as an “end tape,” is provided at the end of the coating film tape. The end tape, which is typically composed of a material such as polyester, is connected between a core and the coating film tape. An example of such a structure is disclosed in unexamined Japanese Patent Publication No. 115229/1994.
The core is adhered to the end tape, and the end tape is adhered to the coating film tape, using short lengths of single-sided adhesive tape. The locations along the lengths of the coating film tape and the end tape where the adhesive tape overlaps one or both tapes are referred to as “adhered sections.” These adhered sections have different thicknesses. For example, where the end tape is connected to the core, the thickness of the adhered section is the sum of the thicknesses of the end tape and the adhesive tape. Where the end tape is connected to the coating film tape, there are two adhered sections, one having a thickness which is the sum of the thicknesses of the coating film tape and the adhesive tape, and the other having a thickness which is the sum of the thickness of the adhesive tape and overlapping portions of the end tape and the coating film tape.
When the coating film tape wound onto a core, the outer windings exert a radial inward pressure on the inner windings. This pressure, referred to herein as “winding pressure,” is concentrated on the adhered sections, due to their uneven thickness. The concentration of winding pressure causes the coating film to become exfoliated from the base material of the coating film tape, and also causes the coating film adhere to the back surface of the base material of an adjacent winding of coating film tape. These conditions cause several problems. First, they can cause uneven transfer of the coating film onto a receiving surface. Second, accumulation, at the tip of the transfer head, of coating film adhering to the back of the coating film base material, causes failure of the tip to exert even pressure against the receiving surface. Third, adhesion of the coating film to the back of an adjacent winding results in resistance to rotation of the reel of transfer tape, making film transfer difficult.
Where the thickness of the single-sided tape is about 60 microns, the above-mentioned problems can be avoided by using a coating film tape with a thickness of 38 microns. However, when the coating film tape is made thinner in order to miniaturize the coating film transfer tool, the resiliency and tensile strength of the base material of the tape are weakened, and detachment of the coating film can occur easily. Furthermore, when the diameter of the core is reduced, the winding pressure tends to become concentrated. Consequently, when a thinner coating film tape is used, the detachment problem becomes more severe.